
class Course:
    def __init__(self,name,building):
        self.name=name
        self.building=building
        self.building.course_add(self)

class Building:
    def __init__(self,name):
        self.name=name
        self.courses=[]
    def course_add(self,course:Course):
        self.courses.append(course)

class College:
    def __init__(self,name):
        self.name=name
        self.buildings=[]
    def buinding_add(self,building:Building):
        self.buildings.append(Building)


